|
The GPS pointer is distinct than benchmark wireless pointers (FM signal/AM pointer, cellular, TV, two way radio, etc.). It is distinct mainly by the allowance of power it has when obtained by your roof/external antenna. If you were standing next to the satellite, you would be able to glimpse a pattern, which is comprised (or known) as the normalized sink function. Why can't you glimpse it? The short answer is you are not standing next to the satellite. The long answer is GPS satellites are 10,898 nautical miles in space and they don't convey with sufficient power for GPS pointers to be as mighty as the terrestrial wireless pointers that you glimpse with your spectrum analyzer. Furthermore, benchmark wireless signals have affirmative SNRs (signal-to-noise ratio). This means they are more powerful than the noise in their band. The GPS pointers have a negative SNR, i.e., they are weaker than the noise in their band. If GPS had a positive SNR, you would likely not need an antenna on your roof. It is likely you could obtain it inside without an out-of-doors antenna, just like your cell phone or AM/FM wireless. But, the GPS signal has a contradictory SNR. By the time it makes it to the earth's surface, it is about 26dB underneath the noise floor of the earth. That is why an external/roof antenna is required. The GPS pointer is available, but it is concealed under the entire disturbance. The GPS signal can be extracted from the disturbance. A usual GPS receiver has roughly 40dB of processing gain. When it looks at the "noise" it can see/detect certain thing. It does this by accomplishing what is called a correlation of the disturbance against the identical ciphers that were used to conceive the GPS (CDMA) pointer. A close analogy would be that of a comb with some of the teeth broken out that represents the pattern. If you comb the disturbance with a comb that is missing the accurate identical teeth as the comb that conceived the pattern...at precisely the right instant, you will get a agree. So what is the bump that you are glimpsing on your spectrum analyzer? What you are glimpsing is the response/shape of the antenna element (it actions like a filter) and the filter answer of the antenna's preamplifier. Their frequency answer has a chime (Gaussian) bend form, so that you glimpse a chime formed bump on your analyzer. The disturbance is formed by the filter, because disturbance is random. It has identical power across the band, so you wind up with disturbance me the form of the filter answer.The GPS signal is there, but it is 26dB below the top of the bump down in the disturbance or roughly 1,024 times lower than the power of the disturbance. If the GPS pointer is 26dB weaker than the pointer when it arrives, is the GPS pointer 26dB below the noise being assessed? No, not inevitably. It is an 'okay" rule of thumb, but hold in brain the exact signal level counts on the bandwidth of your system, the accurate gains of all apparatus, their disturbance figures. skycaddie sg4Online offers Golf GPS Rangefinder devices as sgx, sgxw, sg3.5, sg4, sg5 units & accessories at best price. Golfers buy Sky CaddieGolf GPS Range finders Now. For More Info: skycaddie sg5.
Related Articles -
Sky Caddy review, SG5 Devices, SG4 gps Units, SG3.5, SkyCaddie SGXw, Sky Caddie SGX, Golf Accessories, Range finder, Belt Clip, Car Charger, Carry Ca,
|
